Each year millions visit Yellowstone National Park to watch the reliably fantastic eruptions of the park's famed geysers. But Old Faithful could stop living up to its name if extended drought in the West becomes the norm, according to a new study in June's issue of the journal Geology.

Not many studies before have tackled how factors like rainfall affect the frequency of geyser eruptions. That's because there are fewer than 1,000 geysers in the world (more than half of which are located in Yellowstone), each one is unique, and only recently has there been enough long-term data to be useful. By analyzing the eruptions of four Yellowstone geysers during the last decade along with climate and river flow data, the researchers showed that in years of high precipitation the geysers erupted more often. During times of reduced rainfall, they spewed hot water and steam less frequently. This makes sense–it's surface water that feeds the magma-heated underground conduits which force Old Faithful's dramatic explosions.

With long periods of reduced rain and snowfall, geyser eruptions could slow or even stop, the study's authors speculate. Of course, there's already evidence that climate change is drying out the West, and many think droughts will only get worse. Yellowstone's geysers are national treasures. It makes me worried--is there anything that climate change won't touch? - Jessica Leber